1. Field of the Invention
The invention relates to a method with which metal components can be uniformly heated, using electron irradiation, over all regions of the metal component in question.
It is accordingly an object of the invention to provide a method and device for heating metal components using electron irradiation in a vacuum chamber that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices and methods of this general type and that, while having a relatively simple structure, allows uniform heating of the metal components in all regions.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a method for evenly heating metal components using electron irradiation in a vacuum chamber, including the steps of providing a vacuum chamber having an electron irradiation device for irradiating the chamber, providing multilayer holding elements in the vacuum chamber, the multilayer holding elements having an outer layer facing the electron radiation, the outer layer resistant to heat and exhibiting heat-absorption properties, and an inner layer facing respective metal components held within the holding elements, the inner layer exhibiting heat-radiating properties, and holding at least one metal component in the vacuum chamber with at least one holding element during electron irradiation heating.
The invention achieves its objectives by a method for heating metal components using electron irradiation in a vacuum chamber in which multilayer holding elements, having an outer layer that faces the electron radiation is resistant to heat and exhibits good heat-absorption properties, and an inner layer that faces the respective metal component and exhibits good heat-radiating properties, are used to hold the metal components in the vacuum chamber.
A significant advantage of the method according to the invention is that the components that are to be heated by electron irradiation can be heated uniformly, even in the regions that, in the vacuum chamber, are covered with respect to the electron irradiation because of the need to hold the metal components. The use of multilayer holding elements with a heat-absorbing outer layer ensures that effective introduction of heat takes place while the inner layer, due to its good heat-radiating properties, successfully emits the heat that has been taken up by the outer layer to the respective metal component. Therefore, metal components can be heated homogeneously in all regions by the method according to the invention.
With the objects of the invention in view, there is also provided a configuration for evenly heating metal components, including a vacuum chamber having an electron irradiation device for irradiating the chamber, and multilayer holding elements for holding metal components in the vacuum chamber during electron irradiation heating, said holding elements having an outer layer facing electron radiation from said irradiation device, said outer layer resistant to heat and having heat-absorption properties, and an inner layer facing respective metal components and having heat-radiating properties.
The invention also achieves its objectives by a configuration for heating metal components using electron irradiation in a vacuum chamber having multilayer holding elements for the metal components. The multilayer holding elements have an outer layer that is exposed to the electron irradiation, is resistant to heat, and exhibits good heat-absorption properties, and an inner layer that faces the respective metal component and exhibits good heat-radiating properties.
The configuration according to the invention is advantageous, in particular, because simply by using multilayer holding elements it enables the metal components to be heated homogeneously. The heating is homogeneous because the multilayer holding elements lead to a good uptake of heat and a good emission of heat to those regions of the metal component in question that are shadowed from the electron irradiation by the holding elements. The multilayer holding elements also can be produced relatively simply.
In accordance with another feature of the invention, the multilayer holding elements may be constructed in different ways. It is considered advantageous if the outer layer is a solid part made from tantalum or molybdenum, on which there is a graphite layer as the inner layer.
The advantage of a multilayer holding element so constructed lies, in particular, in the fact that the solid part made from tantalum or molybdenum successfully absorbs the heat applied by the electron irradiation and has low radiation losses. Moreover, such a solid part is heat-resistant and has a property that the graphite layer can be applied thereto with good thermal conductivity. For its part, the graphite layer is advantageous in that it has a high heat-radiation capacity.
In accordance with a further feature of the invention, the outer layer is a solid part made from a metal that tends to form thermally highly stable oxides and on which there is an oxide layer of the metal as the inner layer. The embodiment of a multilayer holding element so configured offers the advantage that the metals that may be considered are able to withstand high temperatures and have a good heat-absorption capacity. The characteristics can be improved still further by the fact that the surface of the solid part, on its side that faces the electron radiation, is improved, for example, by sand-blasting. The oxides ensure good radiation of heat. Moreover, the use of metals tending to form thermally highly stable oxides as the material for the solid part has the advantage that the formation of the oxides may take place while the multilayer holding elements are in use in the vacuum chamber, during the heating process, so that such multilayer holding elements can be produced particularly easily. Moreover, the considerable oxide formation leads to the automatic annealing of possible surface defects and increases the reproducibility of the heating process. The oxide layer is advantageously removed on the outer side of the solid parts to avoid radiation losses.
Chromium, nickel, or aluminum are particularly suitable as metals tending to form thermally highly stable oxides. Thus, in accordance with an added feature of the invention, the metal includes chromium, nickel, and aluminum, and alloys thereof
In accordance with a concomitant feature of the invention, a ceramic layer is disposed on an outside of the solid part. It has proven advantageous if multilayer holding elements with an oxide layer as the inner layer bear a ceramic layer on the outside of the solid part because such a ceramic layer has very good heat-absorption properties but poor heat-conduction properties.
Other features that are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a method and device for heating metal components using electron irradiation in a vacuum chamber, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.